It is possible you’re about to make a very costly error.
I don’t know where you’re going and I frankly don’t need to know either.
For your PPL you require an M1 visa, you may even have it already.
As far as I am aware an M1 visa cannot be transferred into a work visa or work permit.
So on an M1 you can train all the way to instructor tor but then you couldn’t work as one.
Do not rely on what schools tell you, they may not always know and it’s not their problem to fix.
A school that can provide an F-1 visa will generally require that you do ALL training with them, from zero.
So a PPL on an M-1 at one school may very well disqualify you from getting an F-1 at another school.
Also…there is a darker side, once a school has you on a (work) visa you are tied to them hand and foot. That can lead to abuse of that situation.
Certain schools in Florida were known to do that.